/Engine/Source/Runtime/CoreUObject/Public/Templates/NonNullSubclassOf.h
Copy Constructor, will only compile if types are compatible
template<typename U, decltype(ImplicitConv< T * >((U *) nullptr))*> TNonNullSubclassOf ( const [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< U > & From )